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Old 08-28-2008, 11:06 PM   #1
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Default Finding Vacuum Leak on Hydra Install question

I fired up my '01 today after the Hydra install and the car idle is around 3k rpm. FM confirmed my belief that this is likely a vacuum leak and I will research it tomorrow.

My question is, do I need to focus on a leak from the TB to the head or the turbo to the head. FM said the vacuum leak could be anywhere from the tubo to the head, this doesn't make sense to me.

I agree a boost leak could be turbo to head, but I thought a vacuum leak would be from the TB to the head.

Feel free to educate me.
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Old 08-28-2008, 11:26 PM   #2
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Spritz some carb cleaner around. When its injested (where the leak is), the motor will want to die.
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Old 08-28-2008, 11:38 PM   #3
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vac leak is between TB and head. Check to make sure you hooked all the vac hoses up. There are several on my 99 in weird places on the IM. Did you hook the brake booster up? 3K is pretty high.
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Old 08-28-2008, 11:49 PM   #4
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Indeed. Now that you're running MAP-based, you can basically disconnect the crossover pipe from the throttle body and the engine will run just fine. There's really no such thing as a vacuum leak prior to the throttle body, since there's nothing critical there- no more airflow meter.

I think Pat's right, this sounds a lot like a vacuum hose, and a big one at that. Popping off one of the little hoses might give you an extra 400 RPM at idle, it won't likely take you to 3,000.
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Old 08-29-2008, 06:43 PM   #5
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Mine did the same thing when I first installed it. Will the idle move at all by manually adjusting screw?
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Old 09-05-2008, 06:23 PM   #6
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Quote:
Originally Posted by JayMX5 View Post
Mine did the same thing when I first installed it. Will the idle move at all by manually adjusting screw?
Still fighting the vacuum leak.

I replaced the insulators at the bottom of the injectors and the car is now idling at 2k instead of 3k, but there is still an idle leak because the car surges instead of holding a steady idle. I have pulled and reseated the injectors twice. Carb cleaner has not changed the idle at any connection points.

I really don't know what to do at this point other than try the injectors one more time, and then start replacing all the vacuum lines.

I'm even considering pulling off the lower intake and re-installing it. I did replace it as part of the install since I am no longer using the link-piggy auxillary injectors.
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